QQTube is a social network service provider with cheap prices. So far I have around 50 orders with them and I'd like to review their services. I've been using their service for YouTube only, so I'll focus on that.

From my experience, the views get delivered within 24 hours.
They will stick. Not a single view has disappeared from any of my videos and months have passed already.
You will get all of your views and they'll get overdelivered by a bit.
Your video will get watched for a minute or so. I've ordered retention views and on a 15 minute video I got 8 minutes average watch time.
Most of the views are from Russia. There are almost no views from 1st tier countries.
The views are not monetizable. You won't earn anything.
The views seem to be safe, even with monetization enabled. Not a single of my accounts got banned.
On one of my retention views orders one half of the views came from unknown sources and the other half came from Safari/Apple Messages apps.

Information about customer service:

Decent response time.
If something doesn't work, you will get a refund.

Referral system:

You can earn money through affiliate commissions by referring people to QQTube. They have a tier referral system, meaning you can earn money from referrals of your referrals.
You will earn 20% from the people that you refer and 5% from the people that your referrals refer.
You will get paid via PayPal or balance on their website.

Overall, I can recommend their service if you plan on ordering YouTube views. I haven't tested other social networks as they seem to be in progress. Sometimes some features get added and removed (they used to offer YouTube subscribers as well).